The Power of Three
by Lozilan
Summary: A new innovation in genetics has far reaching consequences for John Watson.
1. Chapter 1

The Power of Three

Chapter one

_.. in which a new innovative technique pioneered in Britain has interesting consequences_.

"How is she?" John asked.

He looked at his wife with deep concern. She had just returned from a visit to her mother. Last spring her mother had been getting symptoms of a neurological syndrome. A few months ago she had been diagnosed with Huntington's, a disease that can be inherited. John feared for Mary.

"She's slowly dying John, but she says it's her dying wish is to see a grandchild before she goes. John, what if I have it? We can't have children; she won't see any grandchild because I can't take the risk!"

"I don't mind if we don't Mary, you know I love you. I just want you to be happy darling." John tried to make his voice as soothing as he could. "We'll get the best care for your mother and she soon won't mind. She will understand."

"But I want to give you a child John! I don't want to take the test, I don't want to know if I have it, but I know I want to have your baby." Mary sat down at the kitchen table and put her head in her hands.

"Then we'll have one dear, shall we?" John came up and gently took her hands in his. He knelt down beside her. "Look, there are new innovations all the time. An old colleague of mine runs a fertility clinic. Shall we go and find out what our options are?" He stood up and looked down to her, lifted a hand to her hair to brush it from her eyes. "Don't worry love, we will find a way."

...

The Angel of Islington Fertility clinic was imposing in the extreme. Glass walls, some of them festooned with stained glass illustrations, were everywhere, looking out over the city of London. Bustling efficient nurses went to and fro, while the receptionist with a false smile took their details. Mary stood holding her husbands hand nervously as the doctor came out and greeted them. She ushered them into a bright pleasant office. John shook her hand warmly and introduced his wife.

"Angela, this is Mary, my wife. Angela was my registrar at 'Bart's with me when I was a junior in the Obs & Gynae ward. Now she runs this clinic and she is one of the best fertility doctors in London."

The doctor motioned them to sit, smiling warmly at Mary and looking speculatively at John. "It's quite a long time since I saw you, Dr Watson. It's good to see you again."

John opened the conversation with some polite chit-chat and after they had caught up, started to explain the reason for their visit. Angela listened to their story with sympathy and understanding.

"Yes," she began, "there are several options you can take. Normally, you may find it's quite expensive to have IVF here with a donated egg, but I have several trials undergoing in this area and if you meet the criteria you won't pay a thing. I am particularly exited about this new series of trials which could mean that the baby you have can still have some of your DNA."

"Really?" Mary asked, wide eyed. John could see hope blossoming in his wife's heart and he felt glad he had brought her. The terrible cloud hanging over her life seemed to lift from her heart as she concentrated on what the doctor was saying.

"So, these series of trials involve taking an egg from you and replacing the nucleus inside with a different one from another gamete and then fertilizing it with your husband's sperm. That way, your baby still has your mitochondrial DNA, which is part of your genetic makeup but will not carry the defect that causes Huntington's."

"So the baby will be still part of me?"

"Yes and more in tune with your body when you are carrying. These trials are very new and you will be one of the first people in the country, in fact in the world, to have a baby produced by three people." Angela leaned back to gauge their reaction.

"Can we do this John?" Mary asked.

"Yes dear, if you want to." He took her hand in his. She gave him a tentative smile. He looked at Angela.

"Can we choose the third person, the one you take the nucleus out of the other egg from, the donated one?"

"Yes," she replied, "whomever you like, so long as they are willing to be tested. The legalities of this procedure are not quite up to dealing with three parents yet. There are three trials, one using a donated egg, one using an egg from a close relative of the potential mother and one using the nucleus from sperm."

"What?" John asked, incredulously.

"Yes, I know, amazingly, the zygote nucleus that is introduced into the mother's egg does not actually have to come from another egg at all. So long as it is suitable, it may just as easily be taken from spermatozoa."

"John?"

Mary looked at her husband who had suddenly gone quiet. "Isn't that something? To think this can be possible! But of course I don't want that, how ridiculous would that be? Anyway honey, I have a headache with all this. Can you sign up and choose the third person? I don't want to know about that part of it."

"Right, Mary -you are sure about this? Leaving it up to me? "

"Of course, just don't tell me is all, I will see you at home. Got some shopping to do anyway. "

She got up, kissed her husband on the cheek and then left. John turned to Angela. His eyes grew slowly darker.

"I've got someone in mind." He said.


	2. Chapter 2

The Power of Three

Part Two

The Angel of Islington Clinic looked busy. John again sat down, looking idly at the walls of glass and stained window decorations. They seemed to consist mainly of long necked storks and angels with feathered wings. The wait seemed longer this time and he idly imagined the person he'd come with transformed into such a creature, floating down gothic arches holding a stork, carrying a child for him. His reverie was intruded upon as the clinic door opened and Angela emerged from her office.

She smiled welcomingly "Come in the both of you! Nice to see you again John. This is to be the donor?"

John nodded as they entered and sank into the expensive leather seats in the consulting room. He looked at his companion. " Angela, this is Sherlock Holmes and he has kindly agreed to be the third person in this .. this "

"More than the third, John, from what you have told me." Sherlock sat forward, looking interested, his long fingers tapping Johns knee remonstratively. "Your wife, as I understand, is merely the 'wrapping' for a child from both of our genetic material." He looked into John's eyes and smiled. "I have agreed to be the other father."

As John looked away, slightly embarrassed, Sherlock turned to Angela.

" Dr Mengel, is this correct? You can take the nucleus out of a sperm cell and introduce it into an egg thus making it essentially an egg itself ? What about the Y chromosome? "

Angela leant forward on her marble desktop and clasped her hands together.

" Your friend has a point John. When fertilization takes place, the chromosomes in the egg and sperm, which both contain half the number each, combine. You see, the only actual difference between the nucleus of an egg cell and a sperm cell with regard to the chromosomes, is that sperms contain either an X or Y chromosome. The Y chromosome can only be produced from males."

So much for basic high school biology, thought John. Sherlock looked bored.

"Human eggs however," she continued, "contain only X chromosomes, gender being dependant on if you are XX or XY. You cannot have YY which could potentially happen this way."

"Exactly" Said Sherlock.

Don't you mean egg sactly?" Joked John.

If Mary had been there she would have groaned. As it was no one said anything. John shut up.

Angela gave him a brief smile. "We can spin the male spermatozoa to stop that happening to some extent, but there is still a small risk."

" We will take it of course, won't we John? I am quite reconciled to having a child with you. I never conceived of the notion before, but circumstances have lead us to this and I would be honoured to have a child this way. What a fantastic experiment!."

John groaned. Angela looked at them both.

" John, your wife, is she ok with this?"

John shifted uncomfortably in his chair. "She said she didn't want to know. That I have to choose." He looked at Sherlock and took a deep breath.

" I have chosen Sherlock and I'm happy with my choice. I can't believe this is actually possible so even with a small risk I want this. Sherlock is right. This is fantastic."

He looked piercingly at his friend and tried to make his point clear." But it's not an experiment, we are talking about a real baby. A real human being that can be produced from three people, and I for one can't think of anyone in the world I would rather that other person be."

He looked at Sherlock, who looked back at him. Their eyes met for a minute. Then John smiled. Sherlock widened his eyes. The air in the room seemed to suddenly loose all oxygen.

Angela cleared her throat. "Right, well its all pretty exciting for us here at the clinic. Your baby, if successful, could be the first of its kind in the world."

Sherlock's eyes took on that look he had when he was in the middle of some grisly experiment, probably involving human body parts. John grew alarmed. Suddenly Sherlock's motivation became clear to him.

" I hope you realise the seriousness of this, Sherlock, this.. this is not just another weird experiment, Sherlock. "

Sherlock sighed. "It is an experimental technique John, perhaps you can publish in the lancet?"

For a minute John thought of his name - him, John Watson , among a string of distinguished authors in an article. If it was a trial, perhaps they would want to publish. Then another kind of article hit his brain.

"Yes, and I can see the Daily Mail headline now. Holmes and Watson create baby together! People will talk."

There was a minute of silence then as Sherlock didn't react. John firmly shook his head. "No way, this is between the three of us".

He laughed darkly. "And my wife is going to kill me when she finds out!"

_Ha! please review, and if anyone scientific is out there, I wonder, is this theorectically possible with this new 3 people thing? _


	3. Chapter 3

The Power of Three

Chapter 3

John nervously stood on the threshold of the flat at Baker Street. He could see Sherlock in deep conversation with a client and did not wish to intrude. It had been a while since he had been on a case with Sherlock and much as he wanted to; he hesitated to stride in as normal. After all, he reasoned, I don't live here anymore and the client's situation may perhaps be a delicate one.

A few minutes later he was forced to stand aside as Sherlock's client left, looking angry and confused. No doubt Sherlock had refused to take the case, although Sherlock, to be honest, had that effect on most people.

As he pushed passed him, the client gave John a searching look. "You're a bloody saint," he volunteered. John smiled back. It hadn't always been easy living with the famous detective.

John was clutching the scan in an envelope. He had come straight from the clinic while his wife had gone home to tell her mother and her friends the news. It had worked. She was with child and John was over the moon.

Sherlock looked over to him languidly from his armchair and held out a pale thin arm in greeting. "By your demeanor John, I can tell it was successful. Come, show me the scan. I want to see my child."

John made his way in and perched on the arm of Sherlock's chair. His heart was bubbling over with joy. He casually stretched his arm over the back of the armchair to steady himself as Sherlock took the envelope and they both peered at the contents. "Here!" John smoothly clicked into professional mode,"It's a bit small, but you can make it out, can't you? Look- there's the head: Mary is so happy! Her mother has taken a turn for the worse, Sherlock, but this news will cheer her up. Mary is her only child."

"Yes, I can see." Sherlock was looking intently at the picture and had the ghost of a smile about him. He nodded to himself. "Sheridan is going to be taller than you. The bone structure is most promising."

" Sh,Sheridan?" John spluttered, taken aback. "You're unbelievable! How do you know it's a 'he' from that picture anyway? And his name will be Hamish by the way; I'm not having a poncey name like that for my son."

"Oh," replied Sherlock airily, "Sheridan is my grandfather's name and also my second name. It is assumed I will pass the name to my heir."

John moved from his precarious position, to sit in the opposite armchair and looked at his friend steadily. "Look, Sherlock, this is not your heir- or whatever- this is _my_ kid, mine and Mary's. You got that? She doesn't even know you're involved."

"But I most certainly am involved, John. I am his father." Sherlock pursed his lips together and tapped the scan thoughtfully. " Hmmm, I cannot decide whether to put him down for Eton or Harrow. What would you prefer?"

John threw up his hands. "What is with you Sherlock? We can't afford private schools! Even you can't, for all your poshness. You can hardly afford this _flat_ on your own."

"No, but Mycroft can; my brother is unmarried and has no plans to take a wife. If he did, it would be solely to provide an heir and as I am now providing one, he will no doubt be at pains to…"

"Are you even listening?" John shouted, rising to his feet. "We have a scan of a 12 week old foetus. You cannot tell from this early scan even what sex it is. "Although," he conceded, "you are somehow correct. It is going to be a boy."

"Two males, do the math John, this indicates it will be male, XY chromosome being much more likely. If somehow the procedure could be undertaken with two females, XX in both, they would be only able to produce a female offspring."

"Yes, yes, brilliant as usual, clever you Sherlock! Oh, and hats off to the Lesbian and Gay community who can now circumvent the last argument against nature to Gay Marriage, no doubt. "

Sherlock lay back in his chair and gave a short laugh as John sat down again. "Indeed so! Now two men will be able to have children together, which actually spring from their loins. John, John! We must be the first couple to do this!" Sherlock got up and began to excitedly pace the room.

"We're not a couple Sherlock."

Sherlock appeared not to have heard. He was in full flow. There was a glow on his face and his eyes were beginning to shine. He spun round. "We must contact Hello magazine. I say, this is one up on Elton, John!"

John watched in fascinated horror as Sherlock flicked his curls back, undid another shirt button and turned to an imaginary camera."What do you think? Shall wear my purple shirt for the photography?" He winked at John, who was looking completely stunned.

Sherlock dropped his gaze, and smiled condescendingly, knowing exactly what effect he was creating. "That is, if it were my thing…but of course- Sheridan must be protected from all this." He paused dramatically, moved his face closer and dropped his voice to a low purr. "It would be good publicity for your blog however, John."

There was a moment's silence as John fought for breath, trying hard to ignore a sudden tingling in his spine. Then he slowly smiled, knowingly.

"You are winding me up, Sherlock!"

"Of course, John!" Sherlock laughed heartily. "Don't worry; your secret is safe with me."

John relaxed visibly.

"I do however, want to know my son. I will defer to your good judgment on this. At some point John, you must tell your wife."

"I know." John sighed. "You have a right to see him of course. I will have you involved in all decisions and you will see him as much as I can manage. I know, I am going to have to tell her at some point, probably after the baby is born. You will not tell Mycroft about this Sherlock, I won't have his interference."

Sherlock said nothing. John had an unnerving flash that Mycroft would probably have known already; perhaps even been involved in engineering the whole thing. He reluctantly put the scan back in its envelope and made for the door.

"John, where are you going? I have just seen a client and agreed to take a case. Will you accompany me on this one? I would value your assistance greatly. It could be dangerous."

"Oh," John hesitated. He really should get back to his wife with the scan. She would want to show her friends the baby. But then… those magic words thrilled him. Again, he could not refuse."Right, Sherlock. You know I am here for you, wherever and whenever you need me."

"How I wish you could be." sighed Sherlock. "Get your weapon from the drawer John, there is murder afoot, no time to lose!"

Sherlock grabbed his coat and scarf, thundered down the stairs and whistled for a cab. John followed his thoughts in a whirl.

"But you don't need me much Sherlock, only when you have cases on. The rest of the time, to be honest, I always felt a bit in the way."He knew Sherlock was probably not listening to him but he carried on regardless. "That's one of the reasons I got married, well, that and I fell in love. I am still on call for you- even if I don't live with you anymore. You can still have me whenever you need me."John bit his lip.

That came out wrong, he thought, but he blundered on."Provided of course I'm not at work , well, even then I will get cover as soon as I can, or on holiday, well, I can cut it short if you need me, or making out with Mary, but.."

The cab had arrived and Sherlock pulled his friend down beside him onto the seat. "Yes, yes, John, I get the picture," he said distractedly. "But, you weren't in the way. Whatever made you feel like that?" He glanced out of the window for a beat then turned back. "No matter, I know I can become engrossed in something and pay no heed to anyone else. Let us leave this conversation on the back burner; we are coming to our destination. Look sharp John, there is a murderer within 50 feet of us and we have to be on our guard."


	4. Chapter 4

The power of three

chapter 4

Mary had just come back from a long visit with her mother. She was tired out and in tears. Her mother was in the last stages of the condition and was now suffering from dementia. It was heartbreaking. She probably would not live many more weeks. Yesterday, her mother seemed not to recognise her. Mary had to come back as it was getting dangerous to be caring for her mother. She was now nearly eight months pregnant.

John was not here.

Where was he? It was too late to be shopping or at work.

Mary's hand trembled a little bit as she picked up the phone. She looked at it with horror. This would be how it was when you feared you may have Huntington's. Every day, a little tremor here, a little stiffness there, all could indicate onset. The first symptoms of the first stages. John was not here. He was out with that friend of his. He was always out with that friend of his.

Mary did not like Sherlock. At first he had been charming to her and he was very handsome. He had been the best man at her wedding and had given a beautiful moving speech about John. How he wished him all the best, hoped they had many children and so on. He was not what he had seemed. Later she had begun to see what was going on. What she saw unnerved her. John seemed to follow him like a little kitten. Sherlock seemed to expect it. Even after their marriage he would not let John alone. They had a big fight about it and it ended with Mary promising John she would not interfere. But she hated how Sherlock treated her husband like some sort of sidekick.

She dialed her husband's iPhone only to get no answer. She put down the phone and made herself a cup of tea, wiping away her sorrow as best she could. A few hours later she tried again. It was past midnight and she had hoped by that time he would be home. The phone rang and Sherlock answered.

"He's asleep!" Sherlock said dismissively when she asked for John. "What is it?"

She felt a sudden pain in her side and couldn't help crying out.

"What's that Mary, is the baby coming?" Sherlock asked. He suddenly seemed concerned.

"I think it's just a Braxton Hicks", she said, "but can you wake him? He should be with me."

"Of course."

She heard someone moan. Sherlock was trying to rouse her John as best he could. He was obviously pretty out of it. Sherlock no doubt, had kept him awake too long on some case or other. She heard her husband protesting in the background.

"What is it Sherlock? Not now, I'm _trying _to get some kip."

"It's your wife John; she is having contractions of some sort,"

"What? Why didn't you tell me! How long have I been asleep? Where am I? Sherlock, what are you… Mary? Having the baby, oh my!"

"Yes, John she may be having our baby. You need to speak to her."

John came on the phone. "Mary? How far apart are they?"

"No, no- it's just a Brixton hick contraction John. Why are you not at home asleep? I've come back this afternoon and I need you. Yes, I have left a message on your phone." She laughed. "I just heard Sherlock say 'she's having _our _baby' to you. So funny! No John, I haven't miss-heard. Come on, get yourself in a taxi and get over here, I'm really sad, John. Mummy's really bad. I need you."

She put down the phone and her hand trembled involuntarily again. What was he doing over there asleep? Why did Sherlock answer his phone? He must have crashed out on that sofa at Baker St. and Sherlock could have been watching him from the chair opposite. She could see a picture in her mind of Sherlock; his hands steepled together, observing her husband as he slept.

She shuddered a little as she imagined John snoring gently on the couch, his mouth partly open, while Sherlock, his strange blue green eyes narrowed, observing John as a tiger might regard his prey.


End file.
